The present invention relates to an improvement in a furnace for burning various granular fuels or materials, particularly, but not exclusively, particles of husk.
Hitherto, there are only few effective and economical husk burning furnaces successfully put into practical use. Namely, the husk burning furnaces proposed have various drawbacks. First of all, it is to be pointed out that, in the conventional husk burning furnaces, the husk particles are completely burned down into white ash because of high burning temperature, and the ash is merged into the hot air coming out from the furnace to contaminate the hot air. In addition, since the conventional husk burning furnaces are not adapted to effect a smoke carbonization of the husk particles, it is not possible to make use of the carbonized husk particles as a fuel nor to return the same into soil. Furthermore, since the conventional husk burning furnaces are constructed to burn the husk particles while the latter are falling from the upper side, the ash is inconveniently scattered to make the discharge of the ash difficult. Finally, it is also to be pointed out that the walls of the furnace are overheated due to the high temperature of the flame to cause a distortion of the furnace chamber and a rapid burning down of the furnace wall resulting in a short life of the burning furnace.